Business Central 365 get max value AL/CAL

 MyTable.RESET;

MyTable.SETCURRENTKEY(Field1,Field2,Field3);
// If Required
MyTable.SETRANGE(Field1,Field1);
MyTable.SETRANGE(Field2,Field2);
IF MyTable.FIND('+') then
message('This is the max. value of Field3: ',MyTable.Field3);