Suppose we have defined a patient object including a true/false field which, for whatever reason, is an important classifier of patients. Let us call it allergic.
Suppose we want to define a patient list which show all and only allergic patients. This is how we would do it:
Select the Patient List in the App Structure
Then, in the Edit panel which appears on the right, click on the Edit icon for "Filtering".
In the dialogue which appears, you can add restrictions (filters) one by one. They combine. That is: if you add multiple filters, then the list will show only instances which satisfy ALL the filters.
We want to add the restriction that the patient must be allergic - that the value of the allergic field must be "true", so we need to add a "Field Value" restriction.
In the dialogue which appears, you simply select the field and then give the condition for that field - so here we are saying allergic has to have the value "true".
When we click Ok, then we see the new filter added, and we click "Ok" again to save and this particular list will no longer display any non-allergic patients.