Example 1.
User1 has read access permissions for directory A only and does not have access permissions for subdirectory B at all.
A User1 r-x
B User1 ---
Example 2.
User1 has access permission only for reading for directory A. Can enter sub directory B, but no files are visible.
A User1 r-x
B User1 --x
Example 3.
User1 can enter the subdirectory C and can read and write files within that subdirectory.
A User1 r-x
B User1 --x
C User1 rwx