use where clause in with inner join in sqlserver

how to use multiple where clause like

first i select values there feedback is not null

select * FROM Tbl_Work

INNER JOIN

Tbl_Client ON Tbl_Work.Client_Id = Tbl_Client.Client_Id

INNER JOIN

Tbl_Employee ON Tbl_Work.Id = Tbl_Employee.Id where Feedback is not null

then i want to select in these selected value

query like this but not work :

select * From (select * FROM Tbl_Work

INNER JOIN

Tbl_Client ON Tbl_Work.Client_Id = Tbl_Client.Client_Id

INNER JOIN

Tbl_Employee ON Tbl_Work.Id = Tbl_Employee.Id where Feedback is not null) where

Company_Name Like '%'+@SearchString+'%' or Department_Name Like '%'+@SearchString+'%'

given error

please help