Can i get the reference to a class object from its variable

This is my class and i have a object of Geometry class a data varible

class Container 
{ 
private:
    std::shared_ptr<Geometry> Geom;
}

if i want to access the Container object from the Geometry variable i can always form the geometry object with Container* as an argument.

Geometry( Container* cont);
Geometry(this);

is it possible for any data variable to return the base object if we dont explicitly define the base object ?