Favorite filters in Preside listings are awesome and I can't live without them. But the more they are used, the more cluttered the UI gets. Here comes the solution:
It would be great to have custom groups of favourite filters. If a fav filter is in a group, then the group is displayed, hiding the fav filters. those related fav filters are visible in form of a drop down menu beneath.
Fav filter groups are display first in list. All fav filters not in a group are displayed afterwards, as done now.
Fav filter groups may be personal, global or shared, much in the same manner as fav filters. The should be freely editable.
I created a small mockup of what that could look like - see here:
Fav Filter Groups can be custom named + sorted. Groups would displayed first, followed by all non-grouped filters (alphabetical order).
It would still be possible to combine multiple fav filters. If one or more filters from a group are applied, this is indicated via a number (e.g. simple text of bootstrap badge). Also the dropdown group control background color changes to indicate that a filter from that group is in use.
In the attached example it could be something like:
Show all records with project managers Jim or Bob (dropdown values not show for this example) and with a turnover of more than 2million pounds.
I think this way it will vastly improve the concept of fav filters - especially on an ever increasing number of those.