To view PDBs from HR schema
I assume that the user is a common user connected to the root container. 

A common user's CONTAINER_DATA attribute determines which PDBs are visible in container data objects

SQL&gt; alter user c##hr set container_data=all container=current;

User altered.

SQL&gt; conn c##hr
Enter password:
Connected.
SQL&gt; select name from v$pdbs;

NAME
------------------------------
PDB$SEED
ORCLPDB

SQL&gt;