Hello Janaka, Did you find a solution to this problem?
I am building an imscc file from tests and question bank content. I am not using Canvas to build my imscc file.
I have images in the Question Stem - these images import to Moodle 3.x properly.
I have images in the Question Answer Options - these images DO NOT import properly. I am experiencing the same issue with $IMS-CC-FILEBASE$ not being converted to the course url path.
If I import this imscc file to Blackboard(classic) these images appear in both the stem and the answer options. The file also imports to Canvas and D2L with no errors.
If you have anything to share that would be very helpful.