I have a sole proprietorship and a llc on file. Can my sole proprietorship file my llc as a dba?

Not sure why you would want to do this. The reason to incorporate or form an LLC is to get the protection of the corporate form of business, shielding you personally from suit. Depending on your marketing and branding objectives, you might wish to consider merging your sole proprietership into the LLC and changing the name of the LLC, if necessary, to do business under your best brand name.