Undo a group by in source data with power bi

I have an input which is grouped and want to undo this in power query ideally. The scenario is as shown below where there is a subheader with a sum, and the line items are below, but do not have the details (code, name) from the header.  

I would like the result to be ungrouped as shown below, where the subheader row is removed all together, and the missing details from the header is replicated to the appropriate line items. 

any help would be appreciated.