Saved Search > Dynamic criteria option "Mine" is not available for custom fields of type list/record that sources in the Class, Department, Location lists

The example below is for Location. Substitute Location for Class or Department if required.

1. Navigate to Lists > Search > Saved Searches
2. Edit the Saved Search.
3. Click Criteria tab.
4. Click Standard sub tab.
5. Select Formula (Numeric) under the Filter column.
6. Enter the formula below on the Formula field:
CASE WHEN {user.locationnohierarchy} = {custom field ID} THEN 1 ELSE 0 END
7. Set the Formula (Numeric) to equal to.
8. Set Value to 1.
9. Click Set.
10. Save & run.

The above criteria will filter the search results based on the user's location setting in their employee record. You may just change the custom field ID to the field ID of the Location on the transactions/items.