suitable Design pattern for implementing complex business

I have a challenge with implementing the complex business of an enterprise system. actually there are a lot of validations and other processes which should accrue as a unit of work. now I have a function with lots of codes and lots of validations.

I couldn't split it into smaller functions because for example, some codes have a result that is needed for the rest. and the result types are different.

bool MyFunc (DataDTO input) {
   DataType1 data1 = _repo1.Get(input.id1);
   var valid1 = checkValidation1();
   DataType3 data3 = _repo3.FindBy(data1.someProp && valid1 == true);
   //...   


   DataType2 data2 = _repo2.Get(input.id2)
   var valid1 = checkValidation2();
   //...

   if (valid1 && valid2)
      saveSomething(data2, data3);

   //...

   //and the rest of code

}

I check the chain of responsibility pattern but I think it is not suitable for me. I tried to split my code but my request to database increased.

what should I do?