A transition is a change from one specific value to another: every time a status went from In Review to Done, or an assignee changed from one person to another.
Shorthand. In the value box, type the two values separated by an arrow:
To Do -> Done
Press Enter or Run. The filter then matches rows whose old value contains
the left side and whose new value contains the right side. Either side may
be left empty: -> Done finds every change into Done from anywhere.
The two boxes. The same filter is available as two fields, “old value contains” and “new value contains”, for values that themselves contain an arrow.
Observed transitions. The grid’s Status column filter lists the status transitions actually present in the rows loaded, as “From → To” with counts, so you can pick one rather than type it.
Saved views and share links carry the transition with the rest of the filter, and the export’s settings sheet prints it under Old value and New value.
Matching is “contains”, case-insensitive, on the stored text of the value. A status is stored by its name, a person by their account ID (shown as a name); to match a person in a transition, filter on the Person dimension instead.