I'm not sure if PSG will qualify for the next phase, especially since they only have 4 points.
PSG is in 25th position in the table. PSG has won only one match and lost three matches in the first 5 matches. PSG has failed to win even against relatively weak opponents. So PSG's chances of qualifying for the next round of the Champions League are very low at the moment.
PSG will face Red Bull Salzburg, Manchester City and Stuttgart in their next three matches in the Champions League. RB Salzburg and Stuttgart are in very bad form at the moment. PSG has a high chance of winning in both these matches. Manchester City is also not in good form now. PSG has a chance of earning points in this match too if PSG's overall performance is stable.
For the matches of PSG against Salzburg and Stuttgart, they will be going all in to have a win in the match and if they do well they’ll even win with a very big margin of goals. Playing again Manchester City will be very unpredictable. Manchester City may not be in form now but at the same time, they’re a team that will not be coming to play this match for a draw or lose, but going all in for a win in order for their chances to the next round to be very much alive. Manchester City and PSG are on the same level of performance to me and if they are able to play well, we will see a competitive game between this two sides. PSG getting to participate in the playoffs will really be their goal now as possibility of getting automatic qualification has been limited. So they will try as much as possible to win all matches.
Maybe they can gain a big advantage since it will be played at Dortmund's home ground. Fan support is very important in such matches, fans are one of the biggest factors for a team to get ahead. Their performance this week was average, they didn't play very well. Maybe they didn't want to get tired for the next match. Otherwise, both teams were strong enough to beat these opponents. It's been a bit of an unfortunate week for both of them. Goals conceded towards the end of the match caused them to lose points 
Fans suppose is really an important part of the success of a game for a team. When you have a lot of support from your fans, it boost morale and confidence by players to win games. Dortmund has been two sided this season as you can’t say their performance is exceptional to the core this season and you can also say that they’re poor in performance and can really go far this season. This match will be evenly played as I see both teams having the same quality of play and will only give what they’ve in this game which I assume to be on an equal scale. The champions league and domestic league games are different but all teams play to their best in the champions league even if they play poor in the domestic league games.