Questions regarding the use of the Linux technique bind mount in Android framework should use this tag.
The concept of bind mounts comes from Linux. Quoting an answer on the Unix and Linux SE,
A bind mount is an alternate view of a directory tree. Classically, mounting creates a view of a storage device as a directory tree. A bind mount instead takes an existing directory tree and replicates it under a different point. The directories and files in the bind mount are the same as the original. Any modification on one side is immediately reflected on the other side, since the two views show the same data.
Unlike a hard link or symbolic link, a bind mount doesn't affect what is stored on the filesystem. It's a property of the live system.
On the Android framework, your phone needs to be rooted to make use of bind mounts. Most probably any root solution works. You will have to choose the Mount Namespace Mode to be Global Namespace for this to work.
If your question is regarding the creation and use of bind mounts in the Android framework, please use this tag. It will also be helpful if you mention the rooting interface you are using in your phone.
You can create a bind mount on a terminal emulator using the following commands:
$su
#mount -o bind <Path_to_original_folder> <Path_to_location_of_bind_mount>
Bind mounts can be destroyed using
$su
#umount <Path_to_bind_mount_directory>
