...
Go to the Extended Search filters page.
In the Actions column, click the More options icon, then select Delete.
Click Delete in the confirmation window to confimconfirm.
Filters are normally deleted in Jira during this process. If the filter was deleted in Jira before the deletion in JQL Search Extensions, you can still delete the filter from a list.
If the filter changed changes owner, the filter is removed from the filters list for the current user, but it is not removed from the system. The new owner can use the filter.
...
Admins can change the owner of shared filters in Jira in a standard way. Once the owner is changed in Jira, you should wait a few minutes for JQL Search Extensions to detect the change.
To change a filter owner:
From the top navigation bar, select Filters > View all filters.
Select the More options icon for the required filter, then select Change owner from the list of options.
Select a new owner, then click Change Owner.
Share a filter
Filters are shared with other authenticated users by default.
...
currentUser(), votedIssues(), watchedIssues() always use the filter owner user session and evaluate to the filter owner user
Filters are reindexed every few minutes, which might delay accurate filter results. Refer to the Extended Search Filters to confirm the last time your filters were synced correctly.
A large number of filters can increase the reindexing time.
...