Port selection codebook enhancements are disclosed for spatial and frequency domain density (FDD) reciprocity. A base station may generate and signal a channel state information (CSI) report configuration including configuration of multiple CSI-reference signal (CSI-RS) port groups, wherein each group includes one or more CSI-RS ports, and each group is associated with one or more codebook subset restrictions (CBSRs). Using the configured restrictions of the CBSRs, served user equipments (UEs) may determine linear combination coefficient feedback based on channel measurements of selected port groups and signals the feedback to the base station. Once the base station receives the feedback it may then determine a hybrid CSI-RS codebook using both the configured CSI-RS port groups and the linear combination coefficients. The base station may then transmit downlink data encoded with a precoding matrix selected from the codebook. Other aspects and features are also claimed and described.