How to collapse sheets query result into a single cell - google-sheets

Question

I have a sheets query that almost does what I want but I need a bit of help to get to the last step.
=QUERY(Sales!$A$2:$C,"SELECT B, SUM(C)
WHERE A='"&B3&"'
GROUP BY B
ORDER BY SUM(C) DESC
LIMIT 3
LABEL SUM(C) ''
FORMAT SUM(C) '$##,##0' "
,0)
This gives me the result in C3:D4. What I want is in E3.
I have two goals. First output the data stacked and joined like in cell E3. Second, the ideal solution is an array formula in C3 that does this for all the 'Partners'.
Sample Data
As always thanks in advance for the assistance and education!

Answer 1

Here is how I solved it. Maybe not the optimal solution because I need to duplicate the calculation, but it does exactly what I need. I've added my solution to the example data.
=REGEXREPLACE(REGEXREPLACE(textjoin(" ♦ ",0,
QUERY({Sales!$A$2:$A,Sales!$B$2:$B,Sales!$C$2:$C},"SELECT Col2, SUM(Col3)
WHERE Col1='"&B3&"'
GROUP BY Col2
ORDER BY SUM(Col3) DESC
LIMIT 3
LABEL SUM(Col3) ''
FORMAT SUM(Col3) '$##,##0' "
,0)
)," ♦ \$"," = \$")," ♦ ",CHAR(10))

Answer 2

One way to accomplish this is creating a custom function in Google Apps Script. To achieve this, follow these steps:
In your spreadsheet, select Tools > Script editor to open a script bound to your file.
Copy this function in the script editor, and save the project:
function GET_TOP_CUSTOMERS(partners) {
const sheet = SpreadsheetApp.getActive().getSheetByName("Sales");
const data = sheet.getRange(2, 1, sheet.getLastRow() - 1, 3).getValues();
return partners.map(row => row[0]).map(partner => {
const partnerRows = data.filter(row => row[0] === partner);
const uniqueCustomers = [...new Set(partnerRows.map(row => row[1]))];
const topCustomers = uniqueCustomers.map(customer => {
return [customer, partnerRows.filter(row => row[1] === customer)
.reduce((acc, current) => {
return acc + current[2] }, 0)];
}).sort((a,b) => b[1] - a[1]).slice(0, 3);
return topCustomers.map(customer => customer[0] + "; $" + customer[1].toFixed())
.join("\n");
});
}
Now, if you go back to your spreadsheet, you can use this function like any in-built one. You just have to provide the appropriate range (in this case it would be B3:B12), as you can see here:
Reference:
Custom Functions in Google Sheets