Possible to group class functions and access them by group in PHP/Codeigniter?

i have a library in my codeigniter4 project, now i want to make my lib with lots of functions more clear.

For that i want to know if its possible to group the functions inside the class-defination by a kind of groups and make them accessable by the groupname.

What i mean. The function “my_classfunction” of the lib “mylib” i normaly use by "$this->mylib->my_classfunction()"

Now i think to make groups of functions and access them by a kind of groupname for example “function funcA is in group testA, funB is in group testB”
and use it in a kind like "$this->mylib->testA->funcA()" – is something like this possible, and if, how?