Dortmund have done well at home this season but overall they are not at the desired level. Nuri Sahin's Dortmund career didn't start well but Dortmund seem to be patient with him. They played the Champions League final last season and unfortunately the team lacks the spirit of last season. Dortmund will have the advantage in this match. The reason is that they are very dominant in home games. Leverkusen, on the other hand, left a great season behind and started this season with a not so good performance. I think Leverkusen, who have shown signs of their old performance in recent weeks, will not be able to dominate against Dortmund.
Yes Dortmund has played very well at home this season and they will probably use this to their advantage in next game. Even though they have not played as well as they did last season when they made it to Champions League final they are still very strong at home and this could make big difference. On the other hand Leverkusen has had trouble playing as well as they did last season even though they have shown some signs of getting better in last few weeks. Because Dortmund plays so well at home and Leverkusen has been inconsistent it is likely that Dortmund will be in control of game and set pace.
Although Borussia Dortmund reached the Champions League final last season, they faced the mighty Real Madrid in that final match. But this season they are not able to perform like that, even they are not able to perform like last season. You mentioned that they played very well at their home ground maybe that's not quite right. Because they had previously played a match against Hoffenheim which was held at their home ground, they could not win that match but the match was a draw. They will face Leverkusen football team on January 11th, Borussia Dortmund are more likely to win this match based on their previous performances.