Merge of Bhakti into Jnana:
According to Bhagavad Gita, verse 10.10 & 10.11 (English translation from Gitapress):
तेषां सततयुक्तानां भजतां प्रीतिपूर्वकम् ।
ददामि बुद्धियोगं तं येन मामुपयान्ति ते ॥
On those ever united through meditation with Me and worshipping Me with love, I confer that Yoga of wisdom by which they come to Me.
तेषामेवानुकम्पार्थमहमज्ञानजं तमः ।
नाशयाम्यात्मभावस्थो ज्ञानदीपेन भास्वता ॥
In order to bestow My compassion on them, I, dwelling in their hearts, dispel their darkness born of ignorance by the illuminating lamp of knowledge.
In above verses, Krishna says that he gives devotees right understanding and jnana which means person following Bhakti path will get Jnana hence they will attain absolute/ultimate truth.
According to Bhagvatam, verse 1.2.7:
वासुदेवे भगवति भक्तियोगः प्रयोजितः
जनयत्याशु वैराग्यं ज्ञानं च यदहैतुकम्
The practice of connecting oneself in devotion unto Vâsudeva, the Personality of Godhead, very soon leads to the detachment and spiritual knowledge that relies on its own power.
Merge of Karma into Jnana:
According to Bhagavad-Gita, verse 4.37 & 4.38:
यथैधांसि समिद्धोऽग्निर्भस्मसात्कुरुतेऽर्जुन ।
ज्ञानाग्निः सर्वकर्माणि भस्मसात्कुरुते तथा ॥
As a blazing ﬁre turns ﬁrewood to ashes, O Arjuna,
so does the ﬁre of knowledge burn to ashes all reactions to material activities.
न हि ज्ञानेन सदृशं पवित्रमिह विद्यते ।
तत्स्वयं योगसंसिद्धः कालेनात्मनि विन्दति ॥
In this world, there is nothing so sublime and pure as transcendental knowledge. Such knowledge is the mature fruit of all mysticism. And one who has become accomplished in the practice of devotional service enjoys this knowledge within himself in due course of time.
I've referenced the (Smriti) Bhagavad Gita for the point of the question. Though I will add the reference from (Shruti) Upanishads....