Add Promise-Chain part in reuseable function

Question

I got a bunch of functions which consist of a simple promise-chain which is mostly individual, anyway for all my functions a small block in the promise-chain is the same for all chains.

Example:

function A() {
  DoSomethingA()
    .then(/* specific then block */)
    .then(/* general then block */)
    .then(/* general then block */)
    .then(/* specific then block */)
}

function B() {
  DoSomethingB()
    .then(/* specific then block */)
    .then(/* general then block */)
    .then(/* general then block */)
}

Now I want to have the "general then block" part be reusable variable/function so I can edit it for all functions at once when required. I just miss how I might handle this in the simplest way. Before and after the "general-then-blocks" there might be a undefined amount of "specific then blocks". The "general then blocks" always appear in this given order and always are exactly after each other.