Try the below CAML Query

   <Where>
      <Or>
         <And>
            <Eq>
               <FieldRef Name='status' />
               <Value Type='Choice'>waiting for approval</Value>
            </Eq>
            <Eq>
               <FieldRef Name='Requestor Manager' />
               <Value Type='Integer'>1</Value>
            </Eq>
         </And>
         <And>
            <Eq>
               <FieldRef Name='status' />
               <Value Type='Choice'>Stage2</Value>
            </Eq>
            <Eq>
               <FieldRef Name='Approver' />
               <Value Type='Integer'>2</Value>
            </Eq>
         </And>
      </Or>
   </Where>

Try the below CAML Query

   <Where>
      <Or>
         <And>
            <Eq>
               <FieldRef Name='status' />
               <Value Type='Choice'>waiting for approval</Value>
            </Eq>
            <Eq>
               <FieldRef Name='Requestor Manager' />
               <Value Type='Integer'>1</Value>
            </Eq>
         </And>
         <And>
            <Eq>
               <FieldRef Name='status' />
               <Value Type='Choice'>Stage2</Value>
            </Eq>
            <Eq>
               <FieldRef Name='Approver' />
               <Value Type='Integer'>2</Value>
            </Eq>
         </And>
      </Or>
   </Where>

Note: You can use U2U tool to build your CAML Query based on your requirements, to download the tool check U2U tool