What is context data?

Context Data, at the "simplest level" is basically extra data that is send on an analytics call... but it will not be included in tracking unless there are specific rules in place to read and process it into tracking items.

For instance, Activity Map data IS content data, and Adobe has explicit rules built into their system to process it and pass it to the reserved dimensions and trigger the Activity Map events.

Where was your screenshot taken? Is this a context variable that is already set and being sent to Adobe? And now you need to know how to use it?

If so, you really don't need Adobe Launch for this... the context variable is already attached to the tracking call.. meaning that you would want to use processing rules to capture and set the value.

In this case, you are sending a "events" (not sure why the event wouldn't just be set directly in Adobe Launch, but no matter)... so lets just say the context variable is sending context variable "events" and its populated with "event101" (and you want to increment event101 in your tracking)

I am guessing that the data is probably directly under the "c" or maybe a special "context" namespace (but likely it's just "c")

In processing rules, you would set a condition to look for your context variable to be set, then you want to set your event If the value contains your event:

However, if you are using low event numbers like 1 or 10 (and set a rule for contains, those would also trigger when event "101" is passed... which is NOT intentional).

You may want to look more at how your context variables are being set... there isn't a lot of benefit to pass events in this manner so that you can process them... the exception to that would be if you didn't want your developers to try and remember all the event numbers, and instead pass context data in "textual information"... as in:

Context:

       events:  "successful login"

In which you would set your processing rules to look for "successful login" and apply the correct event ("event22 for instance).

Now, if you are asking how to set context variables in Adobe Launch, then you would need to use the custom script areas of Launch to set the values. Here is a help document on setting context data: https://experienceleague.adobe.com/docs/analytics/implementation/vars/page-vars/contextdata.html

Basically you would set 

s.contextData["example_variable"] = "Example value";

Context Variables are more often used in Mobile App development, where the SDK doesn't set eVars and Props, etc directly, but relies on processing rules to map the context variables to the appropriate tracking... but that doesn't mean that context data can't be used on the web, but it does tend to be more complex; so be sure if you are going to use it, you have a clear understanding of what is happening and ensure that you fully test everything end to end to ensure all the proper mappings have been used.