Quick filter
Quick filters are saved JQL to filter out the Jira issues which don’t much the conditions. You can use filters in Schedule, Timeline and Gantt
All users who have access to the board can view and use the quick filters, on the toolbar click on Filter to enable or disable filters on the list

Create quick filter
Project admin role is required on project board and Jira admin role is required on program board to create quick filter .
From board go to Board Settings → Quick Filters

Click Add button to create a new filter

Enter the filter name, the JQL and description.
Scope if Global is checked the filter will be available for all boards in Jira instance
Default: if the filter is checked as default it will be always ON for all users on the Scheduler, Timeline and Gantt. Only admin can edit to make it not default.