Is there a translation of the Bible into Hebrew that is based on the LXX+NT? What I mean by my question is this: Has the Septuagint and the Greek New Testament both been translated into Hebrew and put together in one volume?
These comments pertain only to the Septuagint portion of the question. OP elaborates in comments:


  I was wondering if anyone has attempted to restore the original Hebrew text on which the LXX was based by back-translating the LXX into Hebrew.


The interest, then, is driven by a text-critical question and requests a reconstructed text.* In the modern era, there are two major projects of which I am aware that have attempted this in some measure:


Emauel Tov's Parallel Aligned Database -- most accessibly available via several major Bible software packages. The so-called "column b" contains the reconstructed text of interest to OP. From the author's introduction:


  Column b contains a selection of retroverted readings, presumably
  found in the parent text of the LXX.  At the same time, column b
  contains some remarks on differences between the LXX and MT in matters
  of translation technique.


Much of his technique is explained in an introductory monograph by the author. 
Although far from a complete LXX back-translation, The Hebrew Bible: A Critical Edition (formerly known as Oxford Hebrew Bible) deserves mention here for anyone interested in the use of LXX for text criticism of the Hebrew Bible. This aim is a complete eclectic edition of the Hebrew Bible. When the editors deem that the "best" reading is found in a Greek text, this will be reconstructed in Hebrew. The project is explained in the prologue.



*By contrast, the Polyglot Bibles mentioned in another answer reproduce and align several received texts. In all cases of which I am aware, the Hebrew in such books is the Masoretic Text, even when it differs substantially from the LXX.