Conditional Drop down

Hi, 

I have 

Tables and Fields:
Employee Table:

Fields: EmployeeID, EmployeeName, PhoneNo, LDAP, JoiningDate, Level

Project Table:

Fields: ProjectID, ProjectName, JoiningDate, ClientID
Client Table:

Fields: ClientID, ClientName
Emp-Proj Table (Join Table between Employee and Project):

Fields: RecordID, ProjectID, EmployeeID, ClientID, EmployeeName, ProjectID-ProjectName

I want to implement form rule 

• • Set a rule like: “When EmployeeID is selected, show only projects from the Emp-Proj Table where EmployeeID matches the selected employee.”
• This will filter the projects based on the employee selection.
• I am unable to implement above rule after relationship establishment to  tables . 
• Please help or share screenshot to implement When EmployeeID is selected, show only projects from the Emp-Proj Table where EmployeeID matches the selected employee.”

Thanks

Bharat