The ten books shown below, all from 2016, fall into the "parallel narratives" category. This is only a selection of what's available. I find it interesting to see how the cover designs position them in the marketplace. Some emphasize the historical aspects, while for others, you'd have little idea from the outward appearance that a good chunk of the book was historical fiction. Of note: the novels in this post were all written by women. None by male authors come to mind immediately, though there must be a few out there.
1888 and 2014; literary fiction centering on a diary kept by blind doctor Zinaida Lintvaryova about her friendship with Anton Chekhov.
1885 and present-day; psychological suspense surrounding a real-life murder case from 19th-century New England, and a woman now living in the house that was the scene of the crime.
2010, 1945, and 1783: stories set in three historical periods intertwine in a tale about Jewish history and a long-lost manuscript for a mysterious Bach cantata.
2015 and 1955, the small-town Midwest and glamorous Hollywood, as a young Ohio woman learns the background to her mysterious, controversial inheritance.
1897 and today; while caring for her ill grandmother, a young woman finds herself compelled to discover the provenance of a broken sculpture she finds that depicts a woman from the Belle Epoque.
1919 and 1999; a woman trapped in a difficult marriage is inspired by her grandmother's bold, carefree life during the Jazz Age.
The WWII years and 2010; at her grandfather's request, a woman travels to Germany to recover something hidden there over 70 years ago, learning about her family heritage in the process.
1888 and present day; two young women over a century apart share a connection to the tragic Johnstown Flood, as well as genealogical link.
Present day and WWII; a modern journalist uncovers the shady history of a Portuguese town by reading a decades-old novel, whose story may not be fiction.
Present day and 18th-century; a high-powered Russian art expert and Catherine the Great, Empress of Russia, are ambitious women in different centuries experiencing problems with their marriages.