We manage our tenant's opportunities queries as such:
Sales person can only see their opportunities and Sales manager can see his whole team's opportunities (picthures 1. Employee & picture 2.manager) .
We made queries by layouts and assigned them to business roles (picture 3.assign layouts)
We have one Sales person that can see his opportunities and one of the managers queries as well.
How can this happen?
Please check if the authorizations for the different objects - opportunities and accounts to start with. What is the rules you are using and does the sales employee have some kind of interference with this particular opportunity and or the account the opportunity is created for.
Queries are more about the fields and the order of the fields that are displayed and the felds for advanced search that can be used. The data shown in the result of the query is based on the underlying objects and the authorizations of the business role linked to the user.