How to plot a time series graph with panel data

Hi everyone. Because I am new to Matlab, sorry if my question is extremely simple. I have a panel data with both time series component (quarterly) and cross-sectional component (countries). Each country in my sample is assigned an ID number. If I want to plot a time series graph for certain countries in my sample, how would I do that? Another thing, how would I plot a time series graph for a group of countries, where my graph would show the average values of my variable of interest across this group of countries over time. Thank you very much in advance

[Adam Danz]

If you attached your data or a sample of your data it would be helpful.