If you just have a master website with no slave sites defined yet, you can try to move it from one directory to another.
Becarefull if you have already create slave site that you have deployed with symbolic links.

If you put your master in a subdirectory of a "primary" domain it is NOT recommended to create a slave in the parent directory like proposed in point 3.
You can not create a children in the parent of your master.

If you want to deploy a slave like in (3) httpdocs then put your master into another directory that is not a subdirectory of you httpdocs.
If you create such slave in the parent directory, you might delete ALL the slave site including the master website if you later decide to change the (3) slave site.

We do not recomment to have a slave site into a parent directory.

"If you want to deploy a slave like in (3) httpdocs then put your master into another directory that is not a subdirectory of you httpdocs."
Confused.
I have root/httpdocs and root/subdomains/httpdocs
1. move root/httpdocs/*.* to root/subdomains/httpdocs/master/ =master.root.de
2. change config paths
3. create fresh install to root/httpdocs/ =www.root.de
4. create slave1 to root/httpdocs/slave1 =www.root.de/navi
5. create slave1_template
6. create children root/httpdocs/navi/slave1/child1; root/httpdocs/navi/slave1/child2

If I summarise your description, this is like you have a person that want to have a children that is fact is your father.
So try create a children that is a father is not good.