BASH: use . instead of a space for command completion

I have bash function directory located at /git/function This is structure:

/git/function/
├── delete
│ ├── delete.dir
│ └── delete.file
├── main.sh
├── get
│├── get.dir.sh
│└── get.file.sh

How to use main.sh

usage: get + space + TAB(to autocomplete from /git/function/get/ directory)
output:
dir file
Next: when I select select get file it runs script from /git/function/get/get.file.sh

#!/bin/bash

# Directory where the functions are located
functiondir="/git/function"

# List of supported commands:
commands=(
  "get"
  "delete"
)

# Function to execute the 'get' command
get() {
  echo "Running $functiondir/get/get.$1.sh"
}

# Function to execute the 'delete' command
delete() {
  echo "Running $functiondir/delete/delete.$1.sh"
}

# Autocompletion function for command names
_completion() {
  # Find all files in the specified function directory with the given command name
  local function_files=$(find "$functiondir/$1" -maxdepth 1 -type f -name "$1.*.sh" -printf '%f\n' | sed "s/^$1\.//;s/\.sh$//")
  
  # Generate autocompletion options based on the found files
  COMPREPLY=($(compgen -W "$function_files" -- "${COMP_WORDS[COMP_CWORD]}"))
}

# Set autocompletion for 'get' and 'delete' commands using the _completion function
complete -F _completion -o filenames "${commands[@]}"

I have couple questions:

• main.sh is sourced from .bashrc
  
• I want to use . instead of space for command completion,
• I need dynamically generate content from sub-dir /git/function/ without adding additional functions to main.sh
• the fist part of the command for example: if I type get.TAB (I should check if sub-dir exist and if true then generate content of this directory /git/function/get as autocomplete)
• if I type delete.TAB (I should check if sub-dir exist and if true then generate content of this directory /git/function/delete as autocomplete)

If you know better solution to dynamically load custom functions I will appreciate if you can share some tips