Using double relative clauses:
That was a proposal. He put forward the proposal at the committee meeting, but the proposal was rejected
That was the proposal (which/that) he put forward at the committee meeting but which was rejected.
Using double relative clauses:
That was a proposal. He put forward the proposal at the committee meeting, but the proposal was rejected
That was the proposal (which/that) he put forward at the committee meeting but which was rejected.
