We currently have a custom object called 'Buildings' then under that we have our Accounts (Standard object) & Opportunities (Standard). We are trying to calculate the total 'Closed MRC' (Monthly Recurring Charge) field on each Opportunity.
I added a new field called 'Sales MRC Total' on the Account, making it a rollup field from the related Opportunities. We now need to add one more rollup field on the custom object Buildings to sum the Total MRC from all the related Accounts under the Building.
I don't think I am able to use rollup fields with custom objects, so I wanted to see if there could be a way to achieve this using apex?