I had the same question and solved it by
1) Assigning a name to each chart (for example, i used “Chart_WL_1”,”Chart_WL_2”… and so on).
2)Assigning a hot key with the two parts. First setting focus on the first chart with the “FocusWindow [the name of your first chart]” command. The second part is assigning the time frame with the command “MinuteChart [time frame]”.
In my case I have six charts that I want to change at the same time with one hotkey, the script to change to five minutes looks like this:
FocusWindow Chart_WL_1; MinuteChart 5;
FocusWindow Chart_WL_2; MinuteChart 5;
FocusWindow Chart_WL_3; MinuteChart 5;
FocusWindow Chart_WL_4; MinuteChart 5;
FocusWindow Chart_WL_5; MinuteChart 5;
FocusWindow Chart_WL_6; MinuteChart 5;
Hope this helps.