Drawing 2D to convert PDF selection area

I have been having this problem for two days now, as I have a drawing document which contains several drawings which I have to convert to PDF separately (Creo 7.10.0.0). I have tried several options, the first one is through print I have selected to print (blue image) but at the moment of checking the PDF seems too small, it appears white or just nothing, I have tried to change the scale, the zoom, format, size, Plot  and nothing works. 

The other option was to go to document>save as PDF and it converts all the drawings into a single page. I don't have the option to choose the area to convert to PDF, it just automatically converts everything in one sheet in PDF. I have searched on youtube but I can't find a solution.

I need to select the area to convert to PDF

Thanks in advance