Hi @tinh ,
I have a group of elements and I'm remeshing those elements with different element size. Once this operation is done the element ids are changed.
Now, I want the IDs of two elements (whose previous ID I have in a list) after remeshing ?
Is it possible to get it ?

How you do 'refine'?
If you have a element list [1 2 3] before refining.
If you split each element into TWO and the last ID of element is 100, logically you get the new ID list [101 102 103 104 105 106]
where:
1 => 101 & 102
2 => 103 & 104
3 => 105 & 106

How you do 'refine'?
If you have a element list [1 2 3] before refining.
If you split each element into TWO and the last ID of element is 100, logically you get the new ID list [101 102 103 104 105 106]
where:
1 => 101 & 102
2 => 103 & 104
3 => 105 & 106
I just tested and I could confirm that my imagination is correct /emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />
Could you give an example about the operation? Maybe 'renumber' panel?