Filters allow you to limit which tickets are sync from a board. For example, let's say you're syncing from project New App to project Design Tasks. And let's say New App has the following tickets:
- Remake logo
- Design header
- Start a FAQ
If you create a filter on New App to only sync tickets with "design" in the title...
Only ticket #2, Design header, will sync and be copied to Design Tasks.
Filters are dynamic and are evaluated on every sync
This can be especially important to remember when filtering on often-changed fields like label or assignee. A ticket will only be synced while it matches the filter. This means if you create a filter to only sync tickets with label "backend", any tickets with the label "backend" will be copied and synced as long as they still have that label. If you remove the "backend" label from the tickets, then those tickets will no longer sync.