How to split a number of Array to number of array list with customize size?

Try this example, where local!array is your initial list of integers, and local!childArrayLength is your desired size for the nested arrays:

a!localVariables(
  local!array: {10,20,30,40,50,60,70,80,90,100},
  local!childArrayLength: 2,
  local!finalSize: ceiling(count(local!array)/local!childArrayLength),
  
  a!forEach(
    items: 1+enumerate(local!finalSize),
    expression: {
      reject(
        fn!isnull,
        index(
          local!array,
          if(fv!isFirst,fv!item,fv!item*local!childArrayLength-local!childArrayLength+1)+enumerate(local!childArrayLength),
          null
        )
      )
    }
  )
)

Try this example, where local!array is your initial list of integers, and local!childArrayLength is your desired size for the nested arrays:

a!localVariables(
  local!array: {10,20,30,40,50,60,70,80,90,100},
  local!childArrayLength: 2,
  local!finalSize: ceiling(count(local!array)/local!childArrayLength),
  
  a!forEach(
    items: 1+enumerate(local!finalSize),
    expression: {
      reject(
        fn!isnull,
        index(
          local!array,
          if(fv!isFirst,fv!item,fv!item*local!childArrayLength-local!childArrayLength+1)+enumerate(local!childArrayLength),
          null
        )
      )
    }
  )
)

great minds think alike, i guess ;-)

Mike, 

Actually I have already adapted a solution which you post in another question form.

It is working perfertly, thanks!

This is also works! thanks Chris

Was going to say! ;)