You can create a query to find all constituents with a certain contact by following these steps:

1. Click Queries
2. Select a category to store this query in (Ex: Base)
3. Click New Query
4. Name the query
5. Select Base for Query Category
6. Select All Constituents for Query
7. Select Journal Entries for Data Return Type
8. Select Match each Criteria for Criteria Matching
9. Under Browse Fields select Journal from the drop down box
10. Click Contact Subject Text
11. Type in the subject of the contact you are looking for
12. Click Save and Preview