Grouping Transactions Quarterly By Client

I have transaction table I am pulling transactions from and can't quite figure out how to get a sum based on a few items.

I am trying to figure out how to show the sum of the InvestorAssumption and group it based on the DealId, then DealTransType and show the sum of the InvestorAssumption.

So I want to see a total of the InvestorAssumption by quarter split up by DealTransType, then DealId.

Not sure how to do this and any help would be greatly appreciated.

Here is my current view.


Code:

SELECT TOP 100 PERCENT dbo.DealTransactions.DealTransId, dbo.DealTransactions.DealId, dbo.DSGvwInvestorPercentage.InvestorID, DATEADD(quarter,
DATEDIFF(quarter, 0, dbo.DealTransactions.DealTransDate), 0) AS TransDateQuart, dbo.DealTransactions.DealTransType,
dbo.DealTransTypes.DealTransTypeName AS TransactionType, dbo.DealTransactions.DealTransAmount,
dbo.DSGvwInvestorPercentage.InvestorPercentage * dbo.DealTransactions.DealTransAmount / 100 AS InvestorAssumption,
dbo.DSGvwInvestorPercentage.InvestorPercentage, dbo.DealTransactions.DealTransDate AS TransDateActual
FROM dbo.DealTransactions INNER JOIN
dbo.DSGvwInvestorPercentage ON dbo.DealTransactions.DealId = dbo.DSGvwInvestorPercentage.DealID INNER JOIN
dbo.DealTransTypes ON dbo.DealTransactions.DealTransType = dbo.DealTransTypes.DealTransTypeId
GROUP BY dbo.DealTransTypes.DealTransTypeName, dbo.DealTransactions.DealTransAmount, dbo.DealTransactions.DealId,
dbo.DSGvwInvestorPercentage.InvestorID, dbo.DSGvwInvestorPercentage.InvestorPercentage * dbo.DealTransactions.DealTransAmount / 100,
dbo.DealTransactions.DealTransType, dbo.DSGvwInvestorPercentage.InvestorPercentage, dbo.DealTransactions.DealTransId,
dbo.DealTransactions.DealTransDate
ORDER BY dbo.DealTransactions.DealId, dbo.DSGvwInvestorPercentage.InvestorID, dbo.DealTransTypes.DealTransTypeName,
dbo.DealTransactions.DealTransAmount