Key tree

A Key tree (also called a decomposition tree) breaks one value down across fields, one level at a time. Use it to find which members drive a total: expand a member to see what it is made of.

Build a key tree

1. In the report header, select Edit. It appears only if you can edit the report; saving is covered on Build a report.
2. In the Visualizations panel, select Key tree from the Tables & cards group. The full catalogue is on Visuals.
3. On the Fields tab, drag a measure into Value, and the fields you want to break it down by into Explain by. One field is enough to start.
4. The tree opens as a single root card showing the total. Select the + on it to add the first level.

Expand the tree

• The + on a member opens Explain by: the fields still available to expand it and, while more than one field remains, High value and Low value.
• Picking a field adds it as the next level beside the member. Expanding a member replaces anything that was below it with the field you picked.
• The root keeps its + only while the tree has no levels yet. On deeper levels the + appears while you hover the level. With nothing in Explain by, the tree says Add a field to Explain by to expand the tree.
• Each level lists its members by value, largest first (with Compare on, by the first side's value), with a bar and a percentage for each member's share of the parent. Hover a member to read its value and share together, for example Furniture: 1,240 (12.5% of parent).
• Selecting a member focuses it: the other members on the level dim, and the levels below break down from it. Selecting a different member moves the focus.
• Clicking a member also filters the report by it while Cross-filter on select is on, which is the default: click the same member again to remove that filter. See Filters, slicers and interactions.
• A level that waits for its parent reads Select a member in the previous level. While it loads, it shows Loading and the field's name; a failed load shows The level could not be loaded, or the failure's own sentence; a member with nothing under it reads No members under this node.
• High value and Low value probe the fields still available and pick the one whose biggest member is the largest or the smallest. While it works, the tile shows Finding the best split and both entries stay disabled; the level then carries a bulb whose tooltip reads Picked by High value or Picked by Low value. When nothing has a member under the node, the tile answers Nothing to split by.

How many members a level loads

• Children per expansion under General > Limits sets how many members each expansion loads. It starts at 10 and goes up to 500.
• When the level holds more members, it adds a button such as Load 10 more (10 of 214). It fetches the next batch of the same size, and the count in brackets is just the loaded number when no total is known.
• Raise the limit to load more per batch; the button follows it, for example Load 50 more. The limits of every visual type are listed on Visuals.

Save the path readers start from

• Arrange the levels you want readers to open on, then select Set as default (tooltip Save this path as what readers open on). The path saves with the report.
• Select Reset to default (tooltip Back to the author's path) to return to the saved path after exploring. Both controls appear only while the tree differs from the saved path, and Set as default needs edit mode.
• Lock a level so readers cannot remove or replace it: on the level header, select the lock (tooltip Lock for readers; once locked, Locked: readers cannot remove or replace it). Readers see a lock marked Locked by the author. A level can be locked once the saved path contains it, and a lock covers the path from the top down to that level.
• Remove this level and everything below on a level header takes the level out and clears the levels to its right. Readers cannot remove a locked level.
• A saved path heals itself: when a field it names leaves the visual, or a field repeats, the path stops in front of it; when a locked level no longer matches the saved path, the tree falls back to the saved path.
• The tree also remembers the path a reader explores, in this browser, for five days, and opens there again. After that, or after a reset, it opens on the saved path.
• The Default path list on the Visual tab shows the saved levels with their lock toggles and a Clear default path action. See Format a visual.

Compare two sets of values

• With Compare on, a level's members show both sides' values beside a difference chip, and the bars and share of parent follow the first side. A dash on a chip means the difference is not available for that member. See Compare mode.

In printed pages and version previews

• Printed pages and version previews draw the tree without its controls and show the root alone. Open the report itself to walk the levels.

Questions, answered

How do I choose which field the tree splits by?

Select the + on the member, then pick a field under Explain by; the field becomes the next level under that member.

Why is the + missing on a member?

The + appears while you hover the level the member sits on. The root keeps its + only until the first level exists, and every member loses it when no field is left to explain by. With Explain by empty, the tree shows Add a field to Explain by to expand the tree.

How do High value and Low value choose a field?

They compare the fields still available and take the one whose biggest member is the largest (High value) or the smallest (Low value). The tile shows Finding the best split while it probes, then marks the level: its bulb tooltip reads Picked by High value or Picked by Low value. If no remaining field has a member under the node, the tree answers Nothing to split by.

What does the percentage beside a member mean?

It is the member's share of the parent member's value, shown with one decimal place, for example 12.5%. Hover the member to read its value and share together: Furniture: 1,240 (12.5% of parent).

My level shows only 10 members. How do I see the rest?

Raise Children per expansion under General > Limits (up to 500) so the next load brings more, or select the Load 10 more (10 of 214) button under the level, which fetches the next batch of the current size.

How do I give readers a starting path?

While editing, build the levels you want them to see and select Set as default. Readers then open on that path, and you can return to it yourself with Reset to default.

What does locking a level do?

Readers cannot remove or replace a locked level. You lock it from the level header (tooltip Lock for readers); readers see a lock marked Locked by the author. A level can be locked once it is part of the saved path, and the lock then covers the path from the top down to that level.

Why did the tree drop a level after I changed the fields?

A saved path keeps only the fields the visual still has, in order. When a field it names has left the visual, or a field repeats, the path stops in front of it, so the tree never breaks down by the wrong field.

Why does the tree open on a different path than I left it?

The tree remembers the path you explored in this browser for five days and reopens there. After that, after a reset, or in another browser, it opens on the path saved with the report.

Does clicking a member filter the rest of the report?

Yes, while Cross-filter on select is on, which is the default. A click applies a cross-filter for the member and the members above it, and clicking the same member again removes that filter. Turn Cross-filter on select off on the Visual tab to explore without filtering.

What does a Key tree show in a printed report or a version preview?

The root alone: those views draw the tree without its controls, so there is nothing to expand. Open the report itself to walk the levels.