The code below should show you an example of what you could do linking 2 pop menus and contents.
Maybe from that you can work out what else you need to do in your situation.
% parent list
items = { 'A', 'B' };
% secondary list
secondList{1} = { 'A1' 'A2' };
secondList{2} = { 'B1' 'B2' };
% create a fig
hf = figure;
% create a anonymous function for the parent list callback
anon = @(x,y,z) set ( z, 'string', secondList{get(x,'value')} );
% create the uicontrol popup menus
h1 = uicontrol ( 'parent', hf, 'style', 'popupmenu', 'units', 'normalized', ...
'position', [ 0 0.0 1 0.2], 'string', {''} );
h2 = uicontrol ( 'parent', hf, 'style', 'popupmenu', 'units', 'normalized', ...
'position', [ 0 0.2 1 0.2], 'string', items, 'Callback', {anon h1} );
