When creating filtered views on SharePoint lists or libraries, sometimes items that shouldn’t appear in the view do appear with filters that combine both AND and OR conditions together. For example here’s an example of a filtered view where I wanted only items with the word test in the title, and in either Pending and In Progress status. The problem is an item without the word Test in the Title is returned in the view:
The problem is the order of conditions determine how the the SharePoint filters work.
When combining OR and AND conditions together, put the OR condition(s) before the AND condition(s):
For more information on setting up filtered views with multiple conditions:
Filtered Views with Multiple Conditions tutorial
OR you can use a Calculated Column to simplify filtered views:
Filtered views with Calculated Columns tutorial