I’m sorry if this has already been asked… I saw that I can go and select single items to add to my reviews, but I would like if possible to also study things sequentially like in the “Study” tab… just not from the very beginning!
Is there a quick way to say that “I know this!” on, let’s say, all of the N5 content?
For now the only way I found is to go through it in “Study”, have the grammar point be added to reviews and only then I can find the “I know this” button. What am I missing?
You can browse all item by going to grammar > Lessons.
From there you can add to review each item, by clicking on add to review and right away you can then click the “i know this” button.
Or if you really know all N5 content, you can go to your settings and change your study level to N4 and then Study will start from the beginning of N4. It might be worth checking through all of N5 though through the Lessons page to make sure you have indeed covered all of it. Remember that there are no official lists of JLPT grammar so what one textbook or class teaches as N5 and whatever another does can be different. (In fact there were some N5 stuff on BP that I didn’t learn in my textbooks until N4 and vise versa.)
Thank you, that’s exactly what I was looking for! 
Thanks also for the advice, I’ll give a look at the N5 grammar points to see if I miss any of those.