sharing-function.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

DiamondStorage storage ds = diamondStorage();
bytes4 functionSelector = bytes4(keccak256("myFunction(uint256)"));
// get facet address of function 
address facet = ds.selectorToFacet[functionSelector]; 
bytes memory myFunctionCall = abi.encodeWithSelector(functionSelector, 4); 
(bool success, uint result) = address(facet).delegatecall(myFunctionCall); 
require(success, "myFunction failed");