Chavacano grammar is considered to be a Spanish-based creole with a largely Austronesian-based grammar. We will have to resort to approximative translations while respecting the Austronesian-based syntax of Chavacano. In this case, you would be using a Chavacano verb form that uses the imperfective aspect (if my understanding of the English tense in question is correct, the verb is supposed to be in an imperfective aspect, since I interpret "continuous" as belonging to the "imperfective" aspect definition), and the only way to do that in Chavacano is to use the pre-verbal imperfective aspect marker ta.
Afterwards, you would use time expressions and other useful particles, words and expression to convey its "perfect" and its "present" meaning. How would I translate your sentence in Tagalog? I would say "Tatlong taon na akong nag-aaral ng Chavacano". In Chavacano, I would translate it as such:
The Glosbe website appears to be following the same translation method that I have just explained. For example:
Chavacano: Si ta sirvi tu con Jehova por cuanto decada ya[...]
English: If you have been answering at meetings for many years[...]
Chavacano: Si tan comento tu na miting por cuanto año ya[...]
Summarizing, the Chavacano equivalent to the English tense in question would be IMPERFECTIVE VERB + "POR" TIME EXPRESSION + "YA", and insert the rest of the components of the sentence while respecting proper Chavacano syntax, putting subjects, objects, etc. between the construction that I have just specified when it is necessary.
I contacted 2 of the co-authors and got a confirmation from 1 of them that they and Ateneo De Zamboanga University no longer have copies for sale since it was last release about 10 years ago.
I will update this when I get a reply from the other author.
Best bet is the one in Amazon.