Methods, systems, and devices for wireless communications are described. The method may include determining multiple transmission beams (e.g., beamformed directional beams) for transmission of an opportunistic or multi-beam discovery reference signal (DRS) over a shared radio frequency spectrum band. A base station may perform a listen before talk (LBT) procedure for the multiple DRS transmission beams, and transmit, based on the LBT procedure, the DRS over the shared radio frequency spectrum band using a set of the multiple transmission beams (e.g., a set that cleared an LBT procedure). In some cases, the LBT may be performed for each transmission beam, or for a union of all transmission beams, associated with the DRS transmission beams. Alternatively, the base station may determine a contention exempt transmission (CET) period for the shared spectrum band and transmit the DRS using the multiple transmission beams during CET period.