The "Comparative Analysis of Mitigation Techniques for Inrush Current of Transformer" mentions "Pre-insertions resistor with capacitor method" as an inrush mitigation technique:
When circuit breakers are opened transformer is isolated from network, residual flux (remanence) remains in transformer and when transformer is energized inrush current will be increased. In order to reduce above affect, capacitors are inserted in primary side of transformer which reduces residual flux...
The presence of residual flux in the transformer is mainly responsible for saturation of transformer core winding result in inrush current phenomenon. In order to reduce the effect capacitor is inserted in series with resistance.
The as  referred "Analitical analysis of transformer inrush current and some new techniques for its reduction" shows a network diagram without showing how to insert the capacitor in circuit:
How does the capacitor in series with resistor circuit look like that reduces the residual flux inrush effect from a three phase two windings star (primary, isolated from network) delta (secondary) isolation transformer?