The slmmethod @slm suggested theis a good method. If If you want to learn another method than it can be done by ssh tunnel also
ssh -t -l gatewayuser -L9997:127.0.0.1:9998 gatewayserver "ssh -l serveruser -D9998 -N internalserver"
ssh -t -l gatewayuser -L9997:127.0.0.1:9998 gatewayserver "ssh -l serveruser -D9998 -N internalserver"
Kindly ignore the poor diagram :)
