Constraining (narrowing) a found set
Constraining a found set lets you narrow find results incrementally, looking for more specific detail as you search your database. To find records based on multiple criteria in separate fields (a logical AND search), perform a find, specify the next criteria, then choose Requests menu > Constrain Found Set.
For example, after searching for all of the employees who work in Sales, you can narrow the search to find all of the employees within Sales named Alvarez.
To constrain or narrow a found set:
See Making a find request.
Choose Requests menu > Constrain Found Set.
FileMaker displays the constrained found set in Browse mode.
To first search for all the employees in Sales, and then constrain the found set to Sales employees named Alvarez:
Perform a find for Sales in the Department field.
Instead of clicking Find, choose Requests menu > Constrain Found Set.
The found set would then consist of employees in Sales named Alvarez.
Related topics 
Extending (broadening) a found set
Finding duplicate values
Finding records based on criteria in a single field