Shanika, workplace bullying has benefited from a lot of recent as well as past attention. Whilst some professions such as those within the medical domain have received adequate focus, others have not. Likewise, the contextualisation of bullying beyond professional boundaries also deserves research attention. Additionally, comparing bullying practices across professions and nation states could also provide enought esearch impetus. Interesting.
Shanika, To clearly understand the gap in the area of bullying, it is very important to read the extant research reviews. The recent reviews will give you some idea on this and talking to working professionals will also give insight into what can be researched.
A very well known gap is the perpetrators' perspective, as most studies are done either on organization or targets. Another gap is further exploring the process of bullying. Most of the process studies are linear, while bullying isn't a linear phenomenon, I am currently working on this. There are also many antecedents, which I believe aren't explored. As I found some antecedents during my thesis for which I couldn't find literature. The thing about workplace bullying is, it is too complex to be fully studied, and if one looks closely they may find a research gap. Obviously the extant literature helps in finding the gap, but sometimes one may observe something in the real world and when they go back and search the literature on it they may realise that it hasn't been studied.
The best and the worst part is, it happens with people all the time and it is highly observable in our day to day life, if one keeps their eye open, they may find something really interesting to be studied.