I am not sure I understand correctly, but if the different entries in your file are separated by consecutive newlines, you can use Perl and paragraph mode:
$ perl -000ne 'print if /keyword/' file
Data engine-1
Data engine-1
Data
Data
Data engine-1 **keyword-1**
Data engine-1
Data engine-3
Data engine-3
Data
Data
Data engine-3 **keyword-1**
Data engine-3