Hi OkHi - thanks for reaching out! In theory you could initialize with something along the lines of below:
Analytics analytics1 = new Analytics.Builder(context, "key1").build();
Analytics analytics2 = new Analytics.Builder(context, "key2").build();
However we do not recommend this - you should only ever initialize ONE instance of the Analytics client. These are expensive to create and throw away, and in most cases, you should stick to our singleton implementation to make using the SDK easier. Further details here. For a possible alternative to send events to different sources, our Repeater destination may be worth considering.