Yes, you are not understanding my explanation which means that you don't understand the concept of bind mounts in Docker.
Think of your host and the container where the application is running as two separate filesystems. In the docker container configuration where it says "Host Path #" you specify the path on your host. Then just under the host path you specify the path it will get inside the container. That path is what the application will see. It's basically a way to symlink a folder on one filesystem to a folder on another filesystem.
So, if you still have /mnt/user/my_share pointing to /Share, when in the application browse to /Share and not /mnt. You should see the content of /mnt/users/my_share in the /Share folder. That is how bind mounts work. You specify a path on the host and then where it will end up in the container.
If you want to make it really easy, just mount /mnt/user to /mnt/user and everything will show up as it is on your host even in the container.
This is the smallest example I can give you to show how it works.
gange@midgard:~/tmp$ touch foo.txt
gange@midgard:~/tmp$ ll
total 0
drwxr-xr-x 1 gange users 14 May 18 23:13 .
drwx------ 1 gange users 250 May 18 23:13 ..
-rw-r--r-- 1 gange users 0 May 18 23:13 foo.txt
gange@midgard:~/tmp$ pwd
/var/services/homes/gange/tmp
gange@midgard:~/tmp$ docker run -v /var/services/homes/gange/tmp:/foo/bar/baz alpine ls -R /foo
/foo:
bar
/foo/bar:
baz
/foo/bar/baz:
foo.txt
Here you can clearly see that my host path `/var/services/homes/gange/tmp` becomes `/foo/bar/baz` in the container.
If you still don't understand I cannot help you further.