Editing a policy target affects other policies
Issue
When you change filters that are added automatically to the applied to field of a new or existing policy, it changes the Applied To targets of other policies as well.
Solution
If you need to change the scoped filter of targets within a policy, then delete the Applied To target that is there and create a new target with the rules needed for that policy.
Additional information
After creating a new policy or modifying an existing one it is possible to change what computers it is applied to under the policy's Applied To field.
In the Applied to section, click All Windows Computers with Application Control Agent Installed (Target).
 Click Add rule to target specific computers.
You can change the targeted computers by adding or subtracting rules for the filter.