To be able to see custom fields in your grid view, and to be able to search for them, the following information will be helpful to know.
When you are creating the custom field, it is important that you have checked off these settings:
Show values: When this is checked, you will be able to toggle this on and off in the settings, to have it show up on the grid view.
Can search values: When this is checked, you will be able to use the search bar to locate the custom field details.
Once you have applied these settings, you will then be able to filter for your Custom Fields when searching for Work and Schedule Requests!