The code below is something I wrote quickly to simulate the problem I'm having with more complex code. I use Row (or Grid) to get the first 2 manipulate variables (a and b) on one line above the plot and I want the other 2 variables (c and d) in one line below the plot. I can get the controls where I want them without Row (or Grid) but then they appear in a column. Whenever I add Row all controls appear to have the same placement. I wasn't able to find any other posts that could help me with this problem.
Manipulate[
f = a*x^3 + b*x^2 + c*x + d;
Plot[f, {x, -4, 4}],
Row[{
Control[{{a, 1, "a"}, 0, 3, ControlPlacement -> Top}],
Control[{{b, 2, "b"}, 0, 5, ControlPlacement -> Top}]
}],
Row[{
Control[{{c, 1, "c"}, 0, 4, ControlPlacement -> Bottom}],
Control[{{d, 0, "d"}, 0, 2, ControlPlacement -> Bottom}]
}]
]
DynamicModule
and build up the grid and control elements. $\endgroup$